generic-ipi/locking: Fix misleading smp_call_function_any() description

Fix locking description: after commit 8969a5ed
("generic-ipi: remove kmalloc()"), wait = 0 can be guaranteed
because we don't kmalloc() anymore.
Signed-off-by: Xie XiuQi <xiexiuqi@huawei.com>
Cc: Sheng Yang <sheng@linux.intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Link: http://lkml.kernel.org/r/51F5E6F8.1000801@huawei.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

kernel/smp.c

@@ -278,8 +278,6 @@ EXPORT_SYMBOL(smp_call_function_single);
  * @wait: If true, wait until function has completed.
  *
  * Returns 0 on success, else a negative status code (if no cpus were online).
- * Note that @wait will be implicitly turned on in case of allocation failures,
- * since we fall back to on-stack allocation.
  *
  * Selection preference:
  *	1) current cpu if in @mask